I have a window unit upstairs. It is a bigger 18,000BTU 220V unit with a wireless remote. What I am looking to do it hack the remote in some way so that I can jsut simply have it turn off and on via the remote. this would let me use a temp sensor that is further away to control it without just pulling the plug on it (compressors dont like that)

Anyone know of a Zwave low voltage relay that can run off of a battery. My idea would be similar to those with a Iris garage door controller and a MyQ garage door opener. I have that and just soldered the open close button to the remote that came with the garage door.

It functions as a z-wave thermostat and can be programmed with your a/c’s remote codes, or learn the IR codes directly if your a/c isn’t in their database. There are a couple device handlers and smartapps for it floating around in the forums (or rule machine would work well, I’d imagine). A little pricey but not much different than the mimolite.

…or something similar into SmartThings. Like the OP, I’m interested in automating a couple of window A/Cs, but I don’t want to go to (quite) the expense of a tado-style solution. The above-linked seem like reasonably priced alternatives… if they work… and if I can support them in SmartThings. Thoughts?

Wouldn’t that require a remote per a/c, or am I missing something with the harmony remotes?

Now that I have a couple of the Aukey (Galaxywind?) devices in-hand, I’m skeptical about integrating them with SmartThings. They use a proprietary app, and connect to wifi directly. (Actually, the Aukey-linked app is currently broken, but the Galaxywind app (iWuHome) works.) I’m not yet familiar enough with SmartThings to know whether there’s a way to add wifi devices to the main interface (or SmartTiles).

Thoughts? Suggestions? Place to start looking/hacking, or should I box these up and send 'em back?

depends. If you want both to come on at the same time you can do it but otherwise you would need one hub per AC unit. Harmony with ST works via activities and only one activity can run at a time per hub